The invention relates to an apparatus for trimming the edges of and for making apertures in three-dimensional hollow work pieces such as moldings.
Such apparatuses are used for making cuts in planes set at an angle to one another, such as occur typically in synthetic plastics moldings for motor vehicles, for example instrument panels, headlining parts, floor and boot carpets, propeller shaft tunnel cladding and the like. In such cases, it becomes necessary to make in the relatively thin molded members which extend in three dimensions both complicated three-dimensional marginal cuts along the edges as well as to cut out apertures in the surfaces of three-dimensional work pieces which may have an irregular shape. The cuts do not need to be made purely at a right-angle to the surface of the moldings or perpendicular to the tangent in the case of curved wall zones, but may also extend obliquely to the wall of the molding. The terms work piece and molding are used interchangeably herein. Since moldings of this type are regularly mass produced moldings, the cuts cannot be made by hand but have to be carried out by machine.
In the case of a known cutting apparatus (DE-AS No. 24 00 897) a plurality of heatable cutting elements are provided which are adapted to be moved as required by a piston-cylinder arrangement, the piston-cylinder arrangements being disposed in a manner which suits the shape of the molding. The cutting lines are in each case sub-divided into a plurality of individual cuts. Therefore, this known cutting apparatus consists of a large number of component parts which have to be aligned relative one another with considerable effort and great accuracy. Furthermore, the parts of the apparatus are adapted to the shape of only one single molding, so that for every differently constructed or rather differently shaped moulding it is necessary to use a completely different cutting apparatus of correspondingly complicated construction.